As referred to herein, watercraft may include any type of water vessel such as powerboats, sailboats, or personal watercraft (PWC) used primarily for recreational purposes, as well as commercial water vessels or ships.
Owners of watercraft have the option of either removing their watercraft from the water for storage on land in between uses or they may keep their watercraft on the water by mooring it to a dock or pier or by stowing it in or on a boat storage device. To reduce the amount of time and effort required to remove, transport, store, and then re-launch the watercraft, many watercraft owners prefer to keep their watercraft on the water where it is more readily available for use. However, mooring a watercraft directly in the water can result in higher maintenance due to the build-up of marine growth and residue on the hull and due to possible physical damage that may be caused by the hull coming into contact with a dock or pier or with other floating objects due to wave, current, or tidal action.
Heretofore there have been two main approaches to protect a watercraft while it is kept on a body of water while not in use. One approach entails lifting the entire watercraft out of the body of water by a freestanding boatlift or permanently installed boat hoist. The other approach entails shielding the watercraft's hull below the waterline with an underwater hull enclosure.
Boatlifts and boat hoists that keep watercraft out of the water share a significant common logistical and handling drawback. Namely, because of their bulk, boatlifts and boat hoists are difficult and expensive to transport, install and remove for storage. Further, in many situations, boatlifts are impractical or impossible to use, as is the case where a watercraft is moored in deep water or where the bottom of the body of water is soft, irregular or severely sloped.
Many watercraft owners have available to them protected marinas or waterways where it may be safe to keep a watercraft moored in the water without benefit of a boatlift. In such situations, a watercraft can be simply secured to a dock or a pier without a fear of damage that may be caused from strong wave action. However, a variety of problems may occur when the hull of a watercraft remains in the water for a protracted period of time as a result of marine growth, which is present in virtually every body of water. In even in the cleanest of fresh water lakes, the formation of slime and algae occurs on the hulls of watercraft as a natural biological process. The formation of slime and algae not only detracts from the appearance of the watercraft, but can also lead to challenging and costly maintenance and impair the speed and performance of the watercraft while underway.
Biofouling, also referred to a bottom fouling, is the process of sea creatures and marine life attaching to the hulls, sides, bottoms, and running gear of the watercraft. The fouling process begins with the formation of slime, which can begin literally within minutes of the watercraft being put into the water. Depending upon the condition of the body of water, additional buildup of slime, grasses, and algae will occur. In saltwater areas, as well as in some bodies of fresh water, the fouling process becomes even more severe. After the slime buildup, additional buildup of mussels, barnacles, tubeworms, hydroids, anemones, sea squirts and other marine creatures can eventually cover the entire submerged surface of the hull. If left unattended, biofouling can severely limit the performance and efficiency of the watercraft and the hull of the watercraft can become severely damaged.
In saltwater areas, the most common method of dealing with bottom fouling is to periodically clean the watercraft's hull and refinish it with an anti-fouling paint. Cleaning the bottom of a watercraft is always a difficult, unpleasant and generally an expensive task. Further, some of the most effective anti-fouling paints have been found to be toxic and environmentally damaging to both the marine environment and in boat yards where old paint is scraped off and new paint is applied.
To address the bottom fouling issue, particularly in saltwater areas, several devices have been developed that inhibit marine growth by providing a watercraft hull enclosure that isolates the watercraft's hull from the surrounding water while it is at rest at a dock or mooring. Such devices provide a water-impervious envelope that is generally complementary to the underwater surface of a watercraft's hull and provides a shield against the surrounding body of water. By isolating the underwater surface of a watercraft's hull from the surrounding water, sunlight, and oxygen replenishment is restricted, which in turn retards the growth of marine organisms. The shield is supported at the waterline by attachment to a structure such as a pier or a dock or to a floating framework. The floating framework, in one example, incorporates rigid tubes with flotation structures attached such as foam. The frame floats at the waterline and the hull shield is suspended below the waterline. Such frames can be difficult to transport, difficult to assemble, and difficult to use.
Underwater hull enclosures protect only the watercraft's hull below the waterline and are suitable for use where the watercraft is moored in relatively calm and protected sites. Unfortunately, although the benefits of underwater hull enclosures are known, they have not enjoyed widespread use because of their generally cumbersome design.
Boatlifts and boat hoists protect the entire watercraft's hull but require structures capable of supporting the entire weight of the watercraft as well as a mechanism to elevate the watercraft to a level above the waterline. Both hull enclosures and boatlifts are made with generally large, rigid, heavy components that make them difficult to transport, set-up, relocate, or remove from the water. Thus, there is a clear need for further development of apparatus and methods for on-the-water storage of watercraft that protects the watercraft's hull both above and below the waterline without the need to utilize complex and relatively expensive lifts and supports.